Attesto.PreAuthorizedCode (Attesto v1.8.0)

OID4VCI pre-authorized code issuance and redemption.

This module is pure logic over an Attesto.PreAuthorizedCodeStore. issue/3 binds the credential issuance context to a short-lived, single-use code. redeem/4 atomically consumes the code before checking expiry or the optional transaction-code PIN and returns the grant context a token endpoint uses to mint a credential access token.

The plaintext code is returned only from issue/3; the store receives its hash. When a transaction code is bound, only its hash is stored as well.

Summary

Types

grant()

issue_attrs()

Functions

issue(store, attrs, opts \\ [])

Mint a short-lived, single-use pre-authorized code and persist it via store.

redeem(store, code, params, opts \\ [])

Atomically consume and redeem a pre-authorized code.

Types

grant()

@type grant() :: %{
  subject: String.t(),
  credential_configuration_ids: [String.t(), ...],
  authorized_scopes: [String.t()]
}

issue_attrs()

@type issue_attrs() :: %{
  :subject => String.t(),
  :credential_configuration_ids => [String.t(), ...],
  :authorized_scopes => [String.t()],
  optional(:tx_code) => String.t() | nil
}

Functions

issue(store, attrs, opts \\ [])

@spec issue(module(), issue_attrs(), keyword()) ::
  {:ok, String.t()} | {:error, :invalid_attrs}

Mint a short-lived, single-use pre-authorized code and persist it via store.

attrs must carry a non-empty :subject, a non-empty list of non-empty :credential_configuration_ids, and an :authorized_scopes list. An optional non-empty :tx_code is stored only as :tx_code_hash.

Options include :ttl (seconds, default 300) and :now (clock override). Returns {:error, :invalid_attrs} for malformed issuance attributes.

redeem(store, code, params, opts \\ [])

@spec redeem(module(), String.t(), map(), keyword()) ::
  {:ok, grant()} | {:error, atom()}

Atomically consume and redeem a pre-authorized code.

The code is taken from the store before expiry or transaction-code validation. A failed PIN check therefore burns the code. Returns a plain grant-context map or an error atom.